1. Field of the Invention
The present invention relates to an image processing apparatus, an image processing method and an image processing program and, in particular, an image processing apparatus, an image processing method and an image processing program for presenting an image to which a user is more amenable to.
2. Description of the Related Art
A typical one of the related-art image processing apparatuses detects a face of a user in an image on a real-time basis, and replaces partly or entirely the image of the face with another image in synchronization with the detected face of the user.
For example, Japanese Unexamined Patent Application Publication No. 2005-157679 discloses a technique of detecting a face image of any size at a high discrimination performance. Japanese Unexamined Patent Application Publication No. 2005-284348 discloses a technique of detecting fast a face image. Japanese Unexamined Patent Application Publication No. 2002-232783 discloses a technique of gluing images of a face of a user pre-captured in a plurality of directions in accordance with an orientation of a face image detected from an image.
A face image pre-captured in this way and a face image detected from an image may be replaced with an avatar produced through computer graphics. By detecting a change in a facial expression of a user on a real-time basis, the expression of the replacing avatar may be synchronized with the change in the facial expression of the user. For example, the openness of the eyes of the avatar or the openness of the mouth of the avatar may be varied in accordance with the facial expression of the user. The smiling degree of the avatar may be varied in accordance with the smiling degree of the user.
Japanese Unexamined Patent Application Publication No. 2007-156650 discloses a technique of generating a natural expression of a face. Japanese Unexamined Patent Application Publication No. 7-44727 discloses a technique of varying a mouth shape in synchronization with a voice.